d3dretrace: Handle ID3D11Device::OpenSharedResource*.

Similar to ID3D10Device::OpenSharedResource code.
specs: Fix DXGI_PRESENT_PARAMETERS::pDirtyRects spec.

It's an array.
specs: Add IDXGIKeyedMutex to interface list.
d3dretrace: Tweak RSGetViewports/RSGetScissorRects spec.

- pNum* arguments are InOut

- Ensure sideeffects is set to false (preventing crash due to the inability
to handle InOut params correctly.

Spotted by Zack.
specs: More tweaks to D3D11 specs.
khronos: Update headers.
specs: Support GL_ARB_direct_state_access.
specs: Support GL_ARB_get_texture_sub_image.
specs: Support GL_KHR_robustness.
specs: Reorder GL_*_IBM params numerically.
specs: Update GL enums.
specs: Add missing 4.5 extensions.

GL_ARB_clip_control and GL_ARB_texture_barrier
specs: Remove redundant _glTexImage*_size variants.
specs/scripts: Allow to filter but one extension in xml2api.py.
d3dretrace: Simplify duplicate code.
image: Support stripping alpha channel when writing PNG images.
gl/d3dretrace: Strip alpha channel when writing PNG images.

The alpha channel is too often bogus, with widespread transparency
preventing viewing the RGB channels.
gltrace: Drop support for user arrays in gl*Draw*Indirect*.

Untested, complicated, and utterly pointless (though I believe not
strictly forbidden) use of GL API.
gltrace: Use a regex for GL draw function names.

More future proof.
specs: Add a few more missing extensions from gl.xml.